Cosmetic methods and compositions for conditioning human skin by topical application to the skin of cosmetic compositions containing red yeast rice extract.
Cosmetic products which improve the appearance of skin are increasingly popular with consumers. Frequently, consumers seek to alleviate or delay the signs of aged or photoaged skin, such as fine lines and wrinkles, dry and sagging skin. Consumers also frequently seek other benefits in addition to anti-aging. A frequent, undesirable skin condition is xe2x80x9coily skin,xe2x80x9d the condition which results from the excessive amount of sebum on the skin. Sebum is skin oil which is produced by sebocytes (cells of the sebaceous glands in the skin) and is then secreted to the skin surface. Oily skin is associated with a shiny, undesirable appearance and a disagreeable tactile sensation. Oily skin affects various age groups. Cosmetic actives which are able to provide both anti-aging benefits and sebum control are highly desirable, both from the manufacturer""s and consumer""s perspective.
In recent years, phytoestrogens (i.e., natural compounds which have estrogen-like activity and which are found in plants) have been increasingly used for cosmetic and therapeutic purposes. Estrogens and synthetic compounds which act like estrogens are known to increase the thickness of the dermal layer and reduce wrinkle formation in the aging skin. Changes in the skin such as skin dryness, loss of skin elasticity and plumpness occurring after menopause are attributed to the lack of estrogen production. Estrogen therapy prevents or slows down many of the changes associated with aging skin (Creidi et al., Effect of a conjugated oestrogen cream (Premarin(copyright)) on aging facial skin, Maturitas, 19, p. 211-23, 1994).
Red yeast rice is also known as Monascus sp. Prior art describes a melanin-formation inhibitor in skin care comprising pigment obtained by culturing Monascus mould (JP 6065038 A). Monascus chitinase has been used to prepare chitosan derivatives with tyrosinase inhibiting activity (JP 4210615 A). Cultured extract of the monascus fungus has been claimed in cosmetic material for skin cleansing (JP 1090109 A) and cosmetics for make-up (JP 10194928). U.S. Pat. No. 4,996,196 mentions red yeast rice used in a dehydration process of hydrous matter.
None of the art described above discloses anti-sebum or estrogenic properties of red yeast rice, or any cosmetic compositions containing red yeast rice in combination with acorbates or retinoids presently claimed.
The present invention includes a skin conditioning composition comprising:
(a) from about 0.001 to about 20 wt. % of red yeast rice extract;
(b) a co-active compound selected from the group consisting of ascorbyl palmitate; sodium ascorbyl phosphate, retinol, retinyl ester, and mixtures thereof; and
(c) a cosmetically acceptable vehicle.
The invention also includes a cosmetic method of controlling oily skin condition and of reducing, preventing or controlling sebum secretion from sebocytes by applying either the red yeast rice extract alone, or the inventive composition, to the skin.
The invention also includes a cosmetic method of stimulating collagen synthesis by fibroblasts in the skin, by applying either the red yeast rice extract alone, or the inventive composition, to the skin.
The invention also includes a cosmetic method of improving the appearance of wrinkled, lined, dry, flaky, aged or photodamaged skin and improving skin thickness, elasticity, flexibility and plumpness by applying either the red yeast rice extract alone, or the inventive composition, to the skin.
The invention also includes a cosmetic method of delivering a phytoestrogen to skin by applying to the skin a cosmetic composition comprising a red yeast rice extract in a cosmetically acceptable vehicle.
The inventive methods and compositions provide control of sebum secretion from sebocytes, improved oil control and improved skin feel, prevent shine and stickiness, while also providing anti-aging benefits which results in reduced appearance of wrinkles and aged skin, improved skin color, treatment of photoaged skin, improvement in skin""s radiance and clarity and finish, and an overall healthy and youthful appearance of the skin.
Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word xe2x80x9cabout.xe2x80x9d All amounts are by weight of the composition, unless otherwise specified.
The inventive compositions contain an extract of red yeast rice. Preferably the extract is an organic solvent extract. The organic extracts are prepared by extracting the red yeast rice powder with a solvent by stirring 1 part of red yeast rice with 2 to 5 parts of the solvent for from 4 to 24 hours at room temperature. Suitable solvents are described hereinbelow. The extracts are clarified by filtration and/or centrifugation, then used as is or dried by evaporation (optionally, under vacuum).
Solvents suitable for the preparation of red yeast rice extract for use herein include, but are not limited to: ethanol, butylene glycol, ethylene glycol, propylene glycolmethanol, hexane, chloroform, dichloromethane, DMSO (dimethylsulfoxide) and ethyl acetate. The preferred solvents are dichloromethane, methanol, or ethanol, or DMSO, or glycol:ethanol mixtures in order to maximize activity. The extract may be further concentrated, fractioned, re-extracted or purified, e.g. by organic solvent extraction or by chromatography.
The red yeast rice extract is employed in the present invention in an amount from 0.001 to 20 wt. %, preferably from 0.01 to 10 wt. %, most preferably from 0.01 to 5 wt. %.
Red yeast rice may be obtained from Shangai International Greenmen Trading Company.
According to one aspect of the invention, red yeast rice extract is employed in a variety of cosmetic methods: to deliver estrogenic activity to the skin; to control sebum secretion or oily skin, and to stimulate collagen production by fibroblasts.
According to another aspect of the invention, red yest rice extract is employed in combination with a co-active compound, in order to obtain substantially improved performance. The co-active compound is selected from the group consisting of ascorbyl palmitate; sodium ascorbyl phosphate, retinol, retinyl ester, and mixtures thereof. The preferred co-active compounds are sodium ascorbyl phosphate (due to its chemical stability) or trans-retinol.
The co-active compound may be obtained from Sigma Chemical Co. or BASF.
The term xe2x80x9cretinolxe2x80x9d includes the following isomers of retinol: all-trans-retinol, 13-cis-retinol, 11-cis-retinol, 9-cis-retinol, 3,4-didehydro-retinol. Preferred isomers are all-trans-retinol, 13-cis-retinol, 3,4-didehydro-retinol, 9-cis-retinol. Most preferred is all-trans-retinol, due to its wide commercial availability.
Retinyl ester is an ester of retinol. The term xe2x80x9cretinolxe2x80x9d has been defined above. Retinyl esters suitable for use in the present invention are C1-C30 esters of retinol, preferably C2-C20 esters, and most preferably C2, C3, and C16 esters because they are more commonly available. Examples of retinyl esters include but are not limited to: retinyl palmitate, retinyl formate, retinyl acetate, retinyl propionate, retinyl butyrate, retinyl valerate, retinyl isovalerate, retinyl hexanoate, retinyl heptanoate, retinyl octanoate, retinyl nonanoate, retinyl decanoate, retinyl undecandate, retinyl laurate, retinyl tridecanoate, retinyl myristate, retinyl pentadecanoate, retinyl heptadecanoate, retinyl stearate, retinyl isostearate, retinyl nonadecanoate, retinyl arachidonate, retinyl behenate, retinyl linoleate, retinyl oleate, retinyl lactate, retinyl glycolate, retinyl hydroxy caprylate, retinyl hydroxy laurate, retinyl tartarate.
The preferred ester for use in the present invention is selected from retinyl palmitate, retinyl acetate, retinyl linoleate and retinyl propionate, because these are the most efficaceous or the most commercially available and therefore the cheapest.
The co-active compound-is employed in the inventive compositions and methods generally in an amount of from 0.001 to 20 wt % preferably from 0.01 to 10 wt %, most preferably from 0.01 to 5 wt. %.
Cosmetically Acceptable Vehicle
The composition according to the invention also comprises a cosmetically acceptable vehicle to act as a dilutant, dispersant or carrier for the actives in the composition in the composition, so as to facilitate their distribution when the composition is applied to the skin.
Vehicles other than or in addition to water can include liquid or solid emollients, solvents, humectants, thickeners and powders. An especially preferred nonaqueous carrier is a polydimethyl siloxane and/or a polydimethyl phenyl siloxane. Silicones of this invention may be those. with viscosities ranging anywhere from about 10 to 10,000,000 mm2/s (centistokes) at 25xc2x0 C. Especially desirable are mixtures of low and high viscosity silicones. These silicones are available from the General Electric Company under trademarks Vicasil, SE and SF and from the Dow Corning Company under the 200 and 550 Series. Amounts of silicone which can be utilized in the compositions of this invention range anywhere from 5% to 95%, preferably from 25% to 90% by weight of the composition.
The cosmetically acceptable vehicle will usually form from 5% to 99.9%, preferably from 25% to 80% by weight of the composition, and can, in the absence of other cosmetic adjuncts, form the balance of the composition. Preferably, the vehicle is at least 80 wt. % water, by weight of the vehicle. Preferably, the amount of water is at least 50 wt. % of the inventive composition, most preferably from 60 to 80 wt. %, by weight of the composition. The preferred compositions are oil-in-water emulsions, containing at least 60%, preferably at least 80% water.
Optional Skin Benefit Materials and Cosmetic Adjuncts
The inventive compositions preferably include sunscreens to lower skin""s exposure to harmful UV rays.
Sunscreens include those materials commonly employed to block ultraviolet light. Illustrative compounds are the derivatives of PABAI cinnamate and derivatives of salicylate. For example, octyl methoxycinnamate and 2-hydroxy-4-methoxy benzophenone (also known as oxybenzone) can be used. Octyl methoxycinnamate and 2-hydroxy-4-methoxy benzophenone are commercially available under the trademarks, Parsol MCX and Benzophenone-3, respectively. The exact amount of sunscreen employed in the emulsions can vary depending upon the degree of protection desired from the sun""s UV radiation.
An oil or oily material may be present, together with an emollient to provide either a water-in-oil emulsion or an oil-in-water emulsion depending largely on the average hydrophilic-lipophilic balance (HLB) of the emollient employed. Levels of such emollients may range from about 0.5% to about 50%, preferably between about 5% and 30% by weight of the total composition. Emollients may be classified under such general chemical categories as esters, fatty acids and alcohols, polyols and hydrocarbons.
Esters may be mono- or di-esters. Acceptable examples of fatty di-esters include dibutyl adipate, diethyl sebacate, diisopropyl dimerate, and dioctyl succinate. Acceptable branched chain fatty esters include 2-ethyl-hexyl myristate, isopropyl stearate and isostearyl palmitate. Acceptable tribasic acid esters include triisopropyl trilinoleate and trilauryl citrate. Acceptable straight chain fatty esters include lauryl palmitate, myristyl lactate, oleyl eurcate and stearyl oleate. Preferred esters include coco-caprylate/caprate (a blend of coco-caprylate and coco-caprate), propylene glycol myristyl ether acetate,. diisopropyl adipate and cetyl octanoate.
Suitable fatty alcohols and acids include those compounds having from 10 to 20 carbon atoms. Especially preferred are such compounds such as cetyl, myristyl, palmitic and stearyl alcohols and acids.
Among the polyols which may serve as emollients are linear and branched chain alkyl polyhydroxyl compounds. For example, propylene glycol, sorbitol and glycerin are preferred. Also useful may be polymeric polyols such as poly-propylene glycol and polyethylene glycol. Butylene and propylene glycol are also especially preferred as penetration enhancers.
Exemplary hydrocarbons which may serve as emollients are those having hydrocarbon chains anywhere from 12 to 30 carbon atoms. Specific examples include mineral oil, petroleum jelly, squalene and isoparaffins.
Another category of functional ingredients within the cosmetic compositions of the present invention are thickeners. A thickener will usually be present in amounts anywhere from 0.1 to 20%. by weight, preferably from about 0.5% to 10% by weight of the composition. Exemplary thickeners are cross-linked polyacrylate materials available under the trademark Carbopol from the B.F. Goodrich Company. Gums may be employed such as xanthan, carrageenan, gelatin, karaya, pectin and locust beans gum. Under certain circumstances the thickening function may be accomplished by a material also serving as a silicone or emollient. For instance, silicone gums in excess of 10 centistokes and esters such as glycerol stearate have dual functionality.
Powders may be incorporated into the cosmetic composition of the invention. These powders include chalk, talc, kaolin, starch, smectite clays, chemically modified magnesium aluminum silicate, organically modified montmorillonite clay, hydrated aluminum silicate, fumed silica, aluminum starch octenyl succinate and mixtures thereof.
Other adjunct minor components may also be incorporated into the cosmetic compositions. These ingredients may include coloring agents, opacifiers and perfumes. Amounts of these other adjunct minor components may range anywhere from 0.001% up to 20% by weight of the composition.
Product Use, Form, and Packaging
In use, a small quantity of the composition, for example from 1 to 100 ml, is applied to exposed areas of the skin, from a suitable container or applicator and, if necessary, it is then spread over and/or rubbed into the skin using the hand or fingers or a suitable device.
The cosmetic skin conditioning composition of the invention can be formulated as a lotion, a cream or a gel. The composition can be packaged in a suitable container to suit its viscosity and intended use by the consumer. For example, a lotion or cream can be packaged in a bottle or a roll-ball applicator, or a propellant-driven aerosol device or a container fitted with a pump suitable for finger operation. When the composition is a cream, it can simply be stored in a non-deformable bottle or squeeze container, such as a tube or a lidded jar. The composition may also be included in capsules such as those described in U.S. Pat. No. 5,063,507 (silicone-based anhydrous composition within a gelatine capsule), incorporated by reference herein. The invention accordingly also provides a closed container containing a cosmetically acceptable composition as herein defined.